1. Field of the Invention
The invention is directed to an electronic balance with a weighing scale, a weighing scale carrier, a system carrier fixed to a housing, an upper and a lower rod, whereby the two rods are connected on one side to the system carrier and on the other side to the weighing scale carrier, to form a parallel guide for the weighing scale carrier and the weighing scale. The balance is also provided with means for adjusting the parallelism of the two rods.
2. Description of the Prior Art
Balances of this type are generally known. The parallelism of the two rods in such scales, is adjusted either by removing material in the area of one or more articulation points, as is described in DE-OS No. 34 22 042, or by a special shaping of the fastening points of the rods, as is described in DE-OS No. 27 10 733 or in another embodiment in DE-OS No. 3003 862. Moreover, DE-OS No. 26 37 539 teaches that the adjusting devices can be divided into a device for coarse adjustment and one for fine adjustment.
However, corner load errors sometimes remain at high resolutions of the balance which can no longer be removed by the known parallelism adjustment of the rods of the parallel guide because these corner load errors are non-linearly load-dependent and can have, for example, the same deviation sign in relation to the center on both sides of the balance. Corner load errors of this type are described, for example, in EP No. 0 080 702, which does indicate a remedy to this problem. However, this remedy is limited in its application to balances with a single-piece parallel guide and results in a weakening of the rod, especially as regards its buckling load.